1. Field of the Invention
This invention relates to gold-plated electronic components and, more specifically, to electronic components of high quality having a thin gold-plated layer and to a method for their production.
2. Description of the Prior Art
Because of its superior physical properties, gold has been widely used as a plated layer on various electronic components. When gold is used in electronic components composed of metallized ceramics, it exhibits good connecting properties in bonding, brazing, soldering, etc. Since gold is very expensive, it is desired to use it in a layer having the smallest possible thickness. In spite of this strong incentive, it has not been realized for one or more reasons. For example, when the gold-plated layer is made thin, an undercoat of plated Ni or Cu, or the metallized layer diffuses into the gold-plated layer because such an undercoat layer or the metallized layer cannot be made compact, i.e., pore free. On the other hand through pinholes in the gold coating, the undercoat layer is degenerated, and discolored under heat. There are further deteriorations in heat resistance and connecting properties, such as the peeling of a silicon tip, deterioration of bonding, and poor cap attachment of an Au/Sn seal. Thus, despite the high cost, a thick gold-plated layer has been required.